A recording method, where an electrostatic latent image is not formed directly on a specially manufactured particular recording paper, but instead where the image is formed on the electrostatic latent image forming material provided as the duplication medium, developed, and then duplicated onto a recording paper for providing the desired output image corresponding to an electrostatic latent image, is currently leading the recording system field because an ordinary paper can be used as the recording paper.
In the case of a recording system of this type, for example, in the electrophotographic recording system, an electrostatic latent image forming material 3 consisting of a conductive basic material 1 and photoconductive insulation layer 2 is at first charged by the positive (or negative) ion in a corona discharger as indicated in the charging process step (a) of FIG. 1. Then, as indicated in the exposing process step (b), the electrostatic latent image forming material 3 is subjected to light irradiation 6, such as by the close exposing or projected exposing method, and thereby an electrostatic latent image 7 corresponding to letters, symbols and figures is formed on the surface of the electrostatic latent image forming material 3.
Then, as indicated in the developing process step (c) of FIG. 1 negatively (or positively) charged developer particles 9 are supplied to the surface of the electrostatic latent image forming material 3 by a developing roller 8 or other means and thereby the developer particles 9 are fixed on the elestrostatic latent image 7. Thus the electrostatic latent image is visualized and a visualized image 10 is obtained.
As indicated in the duplication process step (d) of FIG. 1 recording paper 11 is laid on the visualized image 10 of the electrostatic latent image forming material 3 and the recording paper 11 is charged with the charges in the same polarity as the latent image by means of a corona discharger 12 for duplication. Thus a visualized image 10 consisting of the developer particles 9 is duplicated on the recording paper 11. Then, as indicated in the fixing process step (e), the surface of the recording paper 11 is heated by a heater, such as an infrared ray lamp 13, and the developer particles are melted or fused on the recording paper 11. A visualized image 10 is thus fixed on paper 11.
The conventional recording method, as indicated in FIG. 1, has the following disadvantages as compared with the method of this invention described later.
First, since development on the electrostatic latent forming material 3 is carried out by using or placing the developer particles 9 thereon with a visualized image then being duplicated on the recording paper 11 by the transfer of the particles 9, the developer particles 9 which are not used for duplication remain on the electrostatic latent image forming material 3 and they contaminate the surface of the electrostatic latent image forming material 3 after repeatedly forming electrostatic latent images on the material 3. Therefore, cleaning of the material 3 is essential in order to prevent such contamination. The application efficiency of the developer particles 9 is thus deteriorated.
In addition, the surface of the electrostatic latent image forming material 3 is easily damaged by the mechanical contact a cleaning brush or the like in the cleaning process.
Moreover, this method results in a shortened expected life of the electrostatic latent image forming material because the mechanical contact of a magnetic brush, etc., to the electrostatic latent image forming material surface is indispensable in the development process. Therefore, the electrostatic latent image forming material replacement frequency inevitably increases and maintenance work is also complicated.
Meanwhile, duplication of the image onto the recording paper is achieved by transferring the electrostatic charges to the recording paper 11 and resultingly the latent image 7 on the electrostatic latent image forming material 3 disappears. Thus, after the duplication process step occurs, it is no longer possible to obtain the desired visualized image when development is attempted again on the electrostatic latent image forming material. For this reason, the series of process steps from (a) to (d) must always be repeated in order to obtain a plurality of duplicated images.